GB2271082A

GB2271082A - Printing presses.

Info

Publication number: GB2271082A
Application number: GB9319394A
Authority: GB
Inventors: Andreas Boehme; Roland Hoell
Original assignee: MAN Roland Druckmaschinen AG
Current assignee: Manroland AG
Priority date: 1992-09-22
Filing date: 1993-09-20
Publication date: 1994-04-06
Anticipated expiration: 2013-09-20
Also published as: GB2271082B; FR2695870B1; FR2695870A1; GB9319394D0; DE4231673C2; DE4231673A1

Abstract

For adjusting the positions of the axis of a roll in printing apparatus, for example in offset printing presses, mechanisms are provided at each end of the roll which permit a straight line radial displacement and clamping of the roll in an attained working position. A double-acting drive (24) coaxial to a roll support (2, 5) acts on a mushroom-shaped control piston (17) and a radially-movable piston (16). The piston (16) serves to shift the roll holder (5) along a roll guide against the force of a spring (10). To clamp the holder in position, an arrangement is provided of a biased support bell (21) and clamps (19) which are wedged between the support bell (21) and control piston (17). A double-acting pneumatic ram (24) is moved in opposite directions either to shift the control piston (17) or the support bell (21), in order to displace the axis of roll (1) in one direction or the other. The housing (12) is rotatable relatively to its support for adjusting the direction in which the roll holder is moved. <IMAGE>

Description

2271082 PRINTING PRESSES The invention relates to prInting presses and

particularly to the adjustment of inking etc rollers in such presses. One such adjustment device is disclosed in DE-B-1250451.

In offset printing presses, both in the inking unit and also in the damping unit. a plurality of rollers are provided which need to be adjusted exactly relative to one another in order to produce good printed product. The extent of the adjustment varies from roller to roller, since the diameters are different and also their surfaces can be hard or soft. Further influences on the is positioning of the rollers relative to one another come from the machine drive. It is particularly important whether the rollers are exactly cylindrical and how strongly, on rolling the printing press cylinders against the rollers of the inking and damping units, reactive oscillations-can be transferred. The so-called channel shock, is of particular importance. If, in a plate cylinder, there is present a so- called cylinder channel for clamping a printing plate mounted on the plate cylinder. then during the rolling of the ink applicator 2 and damping applicator rollers against the cylinder, in the region of the cylinder channel the counterpressure falls away, and this can generate movement in the roller bearing. Up to now elastic positioning of roller bearings has always been provided whereby the rollers can be set in each case with an adjustable spring force against a neighbouring roller. The springs used for the biasing cannot, however, prevent oscillation or jumping of the rollers. If one chooses very stiff springs, jumping is improbable but then the rollers cannot any longer be adjusted finely and optimally relative to one another.

Resilient adjustment roller mechanisms are known, such as is from DE-A-3910827, for the linearly guided positioning of rollers against other rollers. The application force is continuously applied or removed by hydraulic elements in controlled fashion.

A device in accordance with DE-B-1250451 on inking units of printing presses avoids these disadvantages. In this device the roller bearing is taken up in a displaceable holder. The holder is received with a dovetail-like guide on a support which in turn is held fixed to the framework. On the support. a pressure-actuated piston is provided which, via an angled lever, is connected with a wedge piece within the guide. Between the wedge piece and the displaceable holder clamping rolls are provided.

By actuation of the pressure medium actuated piston, with the aid of the wedge piece and clamping rolls, the holder can be clamped with respect to the support. Thereby the position of the roller is determined and secured against impermissible movement. To release the clamp. the pressure against the pressure actuated piston is relieved, whereby a return spring shifts the wedge piece into the release position. The unit is constructed in comparatively complex fashion and because of movement limits, return spring turning lever intermediate members, and very complex guiding elements, is very expensive.

Above all, however, it cannot be ensured that the shiftability of the holder can be undertaken without binding. This would, however, be necessary in order to achieve fine adjustment of the rollers. Additionally the device, because of its large cross-section, is not suited for the necessarily-crowded construction of an inking unit with many rollers. Additionally the positioning unit of the rollers is obviously limited to the predetermined shifting direction of the mounting. which is substantially diminishes the possibility of using the unit. Finally, a defined adjustment is possible only by means of additional manipulations on the plate cylinder, because a special adjusting plate is necessary.

The object of the invention is to provide for the rollers and inking units of damping units of printing presses to be both finely adjustable and also protected against oscillations, while being of small volume.

Accordingly the present invention provides a printing press which is as claimed in the appended claims.

It is particularly advantageous for the bearing to have substantially the same diameter as a normal roller bearing. The adjustment of the bearing can be matched in simple fashion to the operating requirements of the printing press, wherein a defined adjustment of the roller relative to its neighbouring roller is automatically possible. The operation can take place by remote control and accordingly is substantially simplified. The roller application pressure is also changeable during machine running. oscillations in the width of the gap between two rollers are suppressed.

Finally the direction of the adjusting force relative to the cooperating roller is also changeable. A special improvement is the use of pneumatic elements which can be used on any printing press, since this energy is available practically throughout. The good reaction possibility with simultaneous sufficient damping of the pressure medium drive is ensured by the use of a plastic slightly deformable material as pressure medium.

An exemplary embodiment of the invention is explained is below with reference to the accompanying drawings, in which:

Figure 1 is a side elevation of a roller with roller bearings according to the invention; Figure 2 is an axial cross-section through one of the roller bearings, shown in Figure 1; Figure 3 is a cross-section along line A-A in Figure 2, but inverted; Figure 4 is a cross-section along line B-B in Figure 2. and Figure 5 is a cross-section along line C-C in Figure 2.

In Figure 1 an elevation of a complete roller 1 with its bearings is illustrated. The roller 1 is supported at both ends in roller locks 2. 2' fixed in roller mountings 3y 3'. The roller mountings 3, 31 are driven by a drive 4, 41 for adjustment or clamping of the roller 1 in a particular position. The whole arrangement has essentially the same diameter as a normal roller mounting except that it is somewhat longer axially.

In Figure 2 the section through the roller mounting 3 together with the drive 4 and the roller lock 2 is illustrated. The roller lock 2 is arranged relative to a roller holder 5 which is provided on its side remote from the lock with two projections 6. Engaged in the constructional space between the projections is a control block 7.

In Figure 3 is illustrated how the control block 7 is connected with the roller holder 5. In the control block 7 ball bushes 8 are set which are displaceable on guide pins 9 fixed in the projections 6. The roller holder 5 is held by means of a capped spring 10 which bears against the control block 7.

The control block 7 itself is fixed by clamps 11 to a housing 12. As illustrated in Figure 4, clamping bolts 13 are provided which press against the clamps 11 in the region of slots 14 in the housing 12. By.releasing the clamping bolts 13, the control block 7 can be rotated relative to the housing 12 by an amount dictated by the length of the slots 14.

The housing 12 is provided in its interior with a pressure chamber 15 which extends in the axial direction and then goes off in the radial direction towards the control block. The pressure chamber 15 is closed in the radial branch by a piston 16. One end face of piston 16 6 faces the surface of the control block 7 which lies opposite the engagement surface of spring 10. The pressure space is closed in the other axial direction by a control piston 17, which is mushroom-shaped, having a frusto-conical control head 18. The control head 18 projects a long way axially out of the control block 7. Arranged around the control piston 17, on the side of the control block 7 remote from holder 5, are four clamps 19. As illustrated in Figure 5, each clamp 19 is pivotally mounted on a pin 20 housed in a passage in the control block 7. The clamps thus lie with one side surface against the control head 18 of piston 17. The opposite side surface rests against a the inner surface of support bell 21 loaded by a spring 22 in the axial direction is against the clamps 19. Spring 22 is supported on an element fixed to the frame. Between control head 18 and the hub of support bell 21 is arranged a pressure piece 22 which sits on the piston rod 23 of a pneumatic ram 24 constituting the drive 4. With the aid of the ram 24, the pressure piece 22 can be used either to shift the piston 17 towards the pressure chamber 15 or to pull the support bell 21 away from the clamps 19.

The device functions as follows:

The roll 1 to be adjusted is adjusted synchronously in each case on drive and operator side. For this to happen, the piston rod of the doubleacting pneumatic ram 24 is shifted whereby, by way of its piston rod the pressure piece 22 moves the control piston 17 and by way of the pressure medium. such as a mass of plastic material, the piston 16. In this fashion, the roller holder 5 is moved radially by means of piston 16. With the aid of the adjustable air pressure on the pneumatic ram 24 any desired position of the axis of roll 1 can be achieved. The roll is secured in this position by the clamps 19. These wedge themselves between the control head 18 on the control piston 17 and the support bell 21 which is always held by the spring 22 in abutment against the clamps 19. Even if the force applied by the pneumatic ram 24 falls away, the piston 16 is maintained in position by the wedging action on control piston 17. The actual clamping force between support bell 21 and clamps 19 as well as the control head 18 is accordingly thereby generated by the counterpressure generated on piston 16 by roll 1, since accordingly the control piston 17 is pushed in between the clamps 19.

is On the return movement, the pressure piece 22 is pulled back by the pneumatic ram 24 and accordingly pulls the support bell 21 away from the clamps 19. This frees the control piston 17 and the roll holder 5 can be retracted again into its null position by the spring 10, whereby simultaneously piston 16 is retracted.

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Claims

1. A device for throwing on and off and adjusting the position of the axis of an inking or the like roll, in which the movement of each end of the roll into its working position is effected by means of pressure medium actuated elements, in which coaxial with the roll support, a pressure medium drive is provided which has a radially-directed drive element acting on the roll support, and an axially-movable control member which, by means of a double-acting drive, can be steplessly shifted over a defined adjustment range and clamped at any point in its range.

is

2. A device as claimed in Claim-1, in which there is a housing fixed to a support frame, and a roll holder adapted to receive a roll trunnion, the roll holder being radially displaceable with respect to the housing, and in which at least one radially-directed spring holds the roll holder in its working position determined by the pressure medium drive.

3. A device as claimed in Claim 2, in which the pressure medium drive consists of a control block arranged in the housing in which there is.movable axially a control piston. and radially a drive piston wherein both pistons seal off a pressure chamber filled with a pressure-transmitting medium, and in which the spring acting on the roll holder is arranged between the control block and a projection from the roll holder.

4. A device as claimed in Claims 3, in which the roll holder is guided by at least one guide pin circumscribed by a ball bush fixed in the control block.

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5. A device according to Claim 3, in which an axiallyloaded support bell is provided into which several pivotal clamps project, wherein the clamps are engaged by the interior of the support bell and the control piston, and which the double-acting drive is arranged so that it moves the control piston in one axial direction and the support bell in the opposite direction.

6. A device according to Claim 5, in which the control piston has a frusto-conical head projecting into the region of the clamps.

7. A device according to Claim 5 or 6, in which the clamps are of rectangular cross-section shape with is rounded corners, and are mounted on pins in the control block, and in which the radial width of the clamps substantially corresponds to the distance between the head of the control piston and the support bell.

8. A device according to Claims 1 to 7, in which the double-acting drive is a double-acting pneumatic cylinder, in which on the piston rod of the pneumatic cylinder a pressure piece is fixed, in which the pressure piece has for setting the roller a first working surface directed against the control head of the control piston, and for setting off the roller has a second working surface lying opposite the first working surface and directed to the inner side of the support bell.

9. A device according to any preceding Claim, in which the housing can be fixedly clamped in various angular positions of the roll holder with respect to the roll axis.

10. A device for adjusting the position of the axis of a roll substantially as hereinbefore described with reference to and as shown in the accompanying drawings.